Quitting time: Neurons that drive sociable behavior in children and teens turn off in adulthood

Amazing stuff!

"... In experiments with mice, researchers observed that Agrp neurons, a type of cell in the brain’s hypothalamus region, play a key role in controlling social behavior in young animals but not in adults. The neurons — which regulate primary survival needs like hunger and maintaining body temperature — drive social needs during youth but slowly lose this role in adulthood. ..."

From the highlights and abstract:

"Highlights

• Agrp neurons encode social need during adolescence but not in adulthood

• Inhibiting Agrp neurons blocks sociability after isolation in juvenile mice

• Social stimuli reduce Agrp neuron activity via olfaction in young mice

• Agrp neuron responsivity to social cues declines during late adolescence

Summary

Social isolation enhances sociability, suggesting that social behavior is maintained through a homeostatic mechanism. Further, mammalian social needs shift dramatically from infancy through adolescence into adulthood, raising the question of whether the neural mechanisms governing this homeostatic regulation evolve across developmental stages.

Here, we show that agouti-related peptide (Agrp) neurons in the arcuate nucleus of the hypothalamus, which are known to drive hunger in adults, are activated by social isolation from weaning through adolescence but not in adulthood. Importantly, the activity of these neurons is critical for social behavior during adolescence:

inhibiting Agrp neurons reduced isolation-induced sociability in juveniles, but not in adults, and

Agrp neuron activation promoted sociability only in young mice.

After isolation, reunion with siblings or other conspecifics, but not unfamiliar adult males or amicable rat pups, rapidly decreased neuronal activity in juveniles, an effect requiring intact olfaction. These findings identify Agrp neurons as a key component of the circuitry governing age-specific social homeostasis."

Quitting time: Neurons that drive sociable behavior in children and teens turn off in adulthood | Yale News "Researchers have mapped the neural signaling that drives social impulses critical to survival in young mammals."

Age-specific regulation of sociability by hypothalamic Agrp neurons (no public access)

Age-specific regulation of sociability by hypothalamic Agrp neurons (preprint, open access)

Graphical abstract